<table border="1" cellspacing="12" width="100%">
<tr>
<td style="width:50%;">
<table width="100%" border="1" cellpadding="10" cellspacing="10" class="box-layout">
<tr>
<td class="box-header">header left</td>
</tr>
<tr>
<td>left</td>
</tr>
<tr>
<td>left</td>
</tr>
</table>
</td>
<td style="width:50%;">
<table width="100%" border="1" cellpadding="10" cellspacing="10" class="box-layout">
<tr>
<td class="box-header">header right</td>
</tr>
<tr>
<td>right</td>
</tr>
<tr>
<td>right</td>
</tr>
</table>
</td>
</tr>
</table>